Touch screens existed in science fiction long before they entered the real-world. Star-Trek: The Next Generation made extensive use of what today are modern touch screens decades before they became common.

Johnson described the touch screen in a seminal paper. Johnson himself never actually created nor patented a touch-screen. Sam Hurst at the U. of KY developed a touch screen sensor in 1971 though it was not see-through until 1974.

The first real touch-screen, with a screen visible behind the touch, was used on Bitzer’s PLATO system, deployed in 1972. PLATO used infrared beams and detected when they were broken rather than more modern systems that detect a screen touch.

In 1983, HP released the HP-150, the first touchscreen computer. BellSouth released the first touchscreen phone, the Simon Personal Communicator, in 1993. By the mid 2000s touchscreens were becoming more mainstream. Finally, with the introduction of Apple’s iPhone in 2007, touchscreens started on the path towards commonplace tech.

Hurst, the early touchscreen pioneer, went on to found a successful touchscreen company, Elographics (now Elo Touch).

Plasma Panel


Donald Bitzer
Gene Slottow
Robert Wilson

Plasma panels form fonts, images, and other patterns using plasma, rather than tubes. The panels are flat, cool, and use less power than CRT tubes.

Bitzer developed the plasma panel as the monitor for his teaching computer, PLATO.

PLATO is a lesser-known fountain of innovation. Along with Bell Labs, Xerox PARC, GE, and Kodak, PLATO created an enormous number of modern technologies. Networked computers, text messaging, online community, and touch-screens all came from PLATO besides plasma panels.

The system was originally developed for Computer Based Training (CBT) by Donald Bitzer and others at the University of Illinois at Urbana-Champaign. PLATO was used for training, much like the web also has an enormous amount of training material. But, much like the web, the system did much more than train people. PLATO is arguably the forerunner of the World Wide Web.

Unlike CRT screens, the panels are flat which helped enable PLATO’s infrared touch-screen technology. PLATO plasma panels were orange with 512×512 single-color pixels, 262,144 total. In contrast, an iPhone XR has 1792×828 red, green, and blue pixels, 4,451,328 total.

Figure 7
Early plasma panel experiment

The panels worked by creating a matrix of wires. When electrical impulses from the X and Y sides of the panel had an intersecting pulse, the plasma glowed orange. Using these early pixels created fonts and even primitive graphics.

Image result for plato display
PLATO panel displaying EMPIRE game

Control Data Corporation, IBM, and TDK Electronics all licensed plasma panel technology.

CRT technology cost less and responded faster than plasma panels. It was decades before plasma panels became less expensive and morphed into a popular consumer electronic in the form of television. Starting in 2005, plasma panels replaced projection televisions and CRT’s as large televisions. Hanging on walls everywhere, the panels dropped quickly in price. They grew in popularity because the background was pure black, unlike other flat panels. However, they tended to “burn-in” — leaving images behind — and eventually dropped in popularity.

Eventually, LCD, LED, and finally OLED technology replaced plasma panels.